The present invention relates to a vehicle door opening device for opening and closing a vehicle door by a motor.
In JP2008-184879A, a vehicle door opening device comprises a resin case (corresponding to “a housing” in this embodiment) attached to a vehicle body as a drive unit. The case has an electric motor as drive source, a reduction-mechanism holding portion for a reduction mechanism that reduces the rotation of the electric motor, a cylindrical drum-holding portion having a driving drum on which a cable attached at one end to a door is wound to transmit power of the electric motor to the door, and a tensioner-holding portion for a tensioner mechanism for applying certain tension to the cable. A cover for closing the tensioner-holding portion is attached to the case, and a fixing portion for mounting the drive unit to the vehicle body is provided.
However, in the vehicle door opening device in JP2008-184879A, as seen along the shaft for the drive drum, a tensioner holding portion is disposed under the drum-holding portion in the case and the electric motor is disposed above the drum-holding portion. The electric motor projects from the casing to increase an occupation area of the drive unit to the vehicle body, which is likely to give adverse effect to the layout of other parts. Even during the transportation of the drive unit, the drive unit is bulky to make transportation efficiency decreased.